Perimenopause is the transition leading up to menopause, marked by fluctuating — not just declining — oestrogen. It can start in your late 30s or 40s and lasts around four years on average, though for some women it runs closer to a decade. Because the changes are gradual and fluctuating, many women go years without recognising what they're experiencing.
Menstrual Changes
Usually the first noticeable sign: periods becoming irregular, shorter or longer cycles, skipped periods, and changes in flow.
Physical Symptoms
- Hot flushes and night sweats: Sudden heat, usually in the face, neck and chest, sometimes with visible flushing and sweating.
- Sleep disruption: Reported by a large majority of women over 40 during this transition, often linked to night sweats but also occurring independently. Magnesium is one of the better-evidenced nutritional supports here — see Best Magnesium for Sleep UK 2026.
- Joint aches and headaches: Linked to fluctuating oestrogen's effect on inflammation and pain sensitivity.
- Breast tenderness and water retention: Driven by hormonal fluctuation rather than a single declining hormone level.
- Skin and hair changes: Thinning, dryness and reduced elasticity as oestrogen — which supports collagen production — fluctuates. Covered in depth in Menopause and Skin: Why Your Skin Changes After 40.
- Bloating and digestive changes: Fluctuating hormones affect gut motility and fluid retention. See How to Reduce Bloating Fast.
Emotional and Psychological Symptoms
Mood changes are among the most prevalent symptoms in this age group, affecting the large majority of women in their 40s and 50s to some degree — irritability, anxiety, low mood, reduced motivation. These are frequently misattributed to stress or life circumstances rather than hormonal transition.
Cognitive Symptoms
Forgetfulness and difficulty concentrating — 'brain fog' — are commonly reported and increasingly recognised as a genuine, hormonally-linked symptom rather than unrelated stress.
Libido and Sexual Wellbeing
Reduced desire, vaginal dryness and discomfort are common and under-discussed. These have both a hormonal component and a broader one — sleep, stress, mood, energy — which is why addressing them benefits from a multi-angle approach. We cover the non-hormonal options in Best Supplement for Women's Energy & Libido in Menopause.
When to See a GP
See a GP if symptoms are affecting your quality of life, if bleeding is very heavy, prolonged, or occurs after sex or between periods, or if you want to discuss HRT. Perimenopause is usually diagnosed on symptoms and age alone, without blood tests.
What Helps Day-to-Day
Alongside any medical treatment, nutritional support helps with specific symptoms: collagen for skin and hair changes (guide), hormone-free botanical support for energy and mood (guide), magnesium for sleep and stress (guide), and gut-health support (guide). Our Anti-Aging Routine for Women Over 40 puts the full daily structure together.
FAQ
How do I know if it's perimenopause or something else?
Irregular periods combined with any of the symptoms above, typically from your late 30s onwards. A GP can rule out other causes — thyroid issues mimic several perimenopause symptoms.
How long does perimenopause last?
Around four years on average, ranging from under a year to roughly a decade.
Do I need HRT?
A personal decision to make with a GP or menopause specialist based on your symptoms, health history and preferences.
Can supplements replace HRT?
No — they work through different mechanisms. Discuss HRT with a healthcare professional if you're considering it.